Final answer:
Option 'c. freezes at 10F' is a physical property of matter, as it represents the temperature at which the substance changes state from liquid to solid without undergoing a chemical change.
Step-by-step explanation:
The question asks to identify which of the listed options is a physical property of matter. A physical property is a characteristic that can be observed or measured without changing the substance's chemical identity. For example, the color of sulfur being yellow or the density of a material are both physical properties because they do not involve changing the substance itself.
Looking at the options provided:
a. it does not burn - This would be a chemical property, as burning involves a chemical reaction with oxygen.
b. produces a gas when placed in an acid - Also a chemical property, since it's describing a reaction with acid.
c. freezes at 10F - This is an example of a physical property, as the freezing point is a temperature at which a substance changes state from liquid to solid without a chemical reaction.
d. the surface turns black in air - This describes a chemical change, likely due to oxidation or another chemical reaction.
Therefore, the correct answer is 'c. freezes at 10F,' which is a physical property of matter.